Dear Lucy: I found your recent question on sunscreen and SPF numbers very interesting. I particularly appreciated the reminder that we need to use a sufficient amount of sunscreen to get the full amount of protection — it’s something I know in theory but don’t always remember to do in practice. But what about spray-on sunscreen? Is it as effective as sunscreen lotions? Is there some metric for how much to use and guidelines for how to apply it properly? —Eat Spray Love
Dear Eat Spray Love: What a great topic! Fortunately, MIT Medical’s always-helpful dermatologist, Allison Larson, was happy to entertain a follow-up question.
According to Larson, a spray-on can be just as effective as a lotion, as long as you use enough, use a high enough SPF, and reapply every couple of hours. While it takes about an ounce of sunscreen to fully cover an adult’s body, amounts can be more difficult to gauge with a spray, which makes it more likely that you’ll use too little or completely miss certain spots.
Larson suggests spraying until your skin glistens. And watch your aim. “Too many people simply spray in the general direction of their skin without paying attention to whether visible liquid is coating the intended area of the body,” she says.
Once you’ve sprayed a generous amount on the appropriate area, Larson advises that you “rub it around enough that you can see it on all areas of the skin before it evaporates. That way you’ll get an even coating and won’t miss any spots.”
In addition, Larson reminds readers to keep the spray away from the face. While safe for skin, some sunscreen ingredients can be irritating or even dangerous if accidentally breathed in. “Use a lotion for your face,” Larson recommends, “or, if you have to use a spray, spray it into your hands, and then rub it onto your face, being careful to avoid your eyes and mouth.”
Then there are those times when a lotion sunscreen is the safer choice. As one Massachusetts man learned the hard way, spray-on sunscreens are flammable and should not be the sun protection of choice at a bonfire or barbeque. A lotion might also be the safer option for a squirmy child who is more likely to inhale some of the mist accidentally.
Lucy thanks Dr. Larson for yet another common-sense answer about sun protection and wishes her readers a happy, safe, and non-sunburned rest of the summer! —Lucy